Qt Multimedia

I repeated the experiment with a build-from-git dev branch reporting "3.31.6" as the version. ( git hash e98fab4c4edfa49debfab549a81862922c0b52e8 ) The results were identical to the earlier experiment. I did get this warning, however: build> ./audiodevices No QtMultimedia backends found. Only QMediaDevices, QAudioDevice, QSoundEffect, QAudioSink, and QAudioSource are available. (I built the Qt library and the test app after installing ffmpeg-free-devel. Though it doesn't appear to be referenced by the app or any of the lib files: build> ldd ~/exp/qt6/root/lib/lib*.so | grep -i ffmpeg build> ) I built with DEBUG support on. Is there something that you'd like me to try? A particular place to poke around?

Hi, How will you be sending them over the network ?

https://github.com/denisgottardello/QtFFmpegPlayer The most part of rtsp cameras work in tcp or udp. Some cameras only udp. Please have a look at the rtsp transport parameter in the main form.

You can run ldd on your libreoffice binary to see which libraries are linked. To enable logging categories, you have the different options describe in the documentation.

@BrianL said in QVideoSink::videoFrameChanged not fired when dragging application window: C:/Qt6/6.10.0/mingw_64/plugins/multimedia/ffmpegmediaplugin.dll You're using ffmpeg backend

@Sikander-Rafiq said in How to provide SRT file to QMediaPlayer: I have manually added Subtitles support in my QT app Would you be so kind as to share some clues about how you did it? I'm building a PySide6 app for editing/translating subtitles, using libmpv to display the video with subtitles. But my app has to save a whole SRT file just to show one freshly-edited subtitle (even when the video is paused). So I'd be interested to know how to make a text overlay that can show text on a video (playing as well as paused). I suspect that you used a text overlay, as I could not see any other way to do it, last time I looked (maybe a year ago). Edit: I hope you meant Qt (cute), not QT (cue tee), as I'm not interested in Apple QuickTime. ;)

I have a similar issue with an opi 5 (rk3588) and I can't get the hardware decoding to work at all. I am guessing that QT is using its own FFMPEG instead of the platform one.

Sounds like something we should improve in Qt 6 then. Could you please submit a bugreport to https://bugreports.qt.io, along with the following info? The Qt version tested Details on your machine (Windows in this case) The media backend used (Windows-native vs FFmpeg) A reproducer (including a video sample that we can use for testing)

Yes, on further investigation. Dolphin and the 'browse' function of Gwenview all give a basic sort of pop-up window to enter the smb credentials, and then don't seem to be able to pass those credentials to ffmpeg to play videos. BUT, if I enter the credentials in Thunar or PCManFM (which has a different style credentials popup) and then double click the file, gwenview opens and can play the files. So I do not know the difference between how the credentials are being saved/stored/shared between the 2 apps, but I do know that one works, and the other broke with the recent update. It's very odd that gwenview cannot do it itself by 'browsing' to the file location, but an external file manager can do it and then send the credentials to the right place for video playback (reminder that basic photo viewing works, it's just the video playback which has broken). I appreciate your time and help, even if it doesn't seem to be qt.multimedia related. Do you know the different methods of how ffmpeg can get permission from other processes?

This definitely looks like a usecase that we should support in Qt Multimedia. Can you check if you are still experiencing this issue, and if you are, could you file a bugreport on bugreports.qt.io? Please include the platform you are using, the Qt version, as well as the media backend you are using (FFmpeg vs. native)

Thank you for the information. I would have responded sooner, but I did not receive a notification of your reply.

@nova_xo I am not sure either. But be aware that some delay is often needed in the pipeline for state or position change. Good you found the solution. I use raw gstreamer code and can find out where waiting is exactly needed. You may need to guess a bit with Qt.

I updated to Qt 6.9.0 and Qt Creator 16.0.1 and problem disappeared!

@FestivalPanda said in Qt6 QVideoSink Not Getting Frames from V4L2 Webcam: 6.2.4 QMultimedia module was basically reworked from Qt6. Qt 6.2.4 might be too new. Better to try the latest Qt6. Also better to use gstreamer + qml sink directly. The example is here: https://github.com/GStreamer/gst-plugins-good/blob/master/tests/examples/qt/qmlsink/main.cpp

Hi, Interesting one ! As is, I don't think so, at least from an "external application" recording point of view. I think it should work if the application is started on the virtual frame buffer.

@Christian-Ehrlicher This was the issue , Thank you very much it is solved now.

@mrkprdo these are ffmpeg libs which need to be installed with your app as well. I guess there are about 8 core libs in total. It is better for you to add all of them. libavutil Utilities Shared code, math functions, cryptography libavcodec Encoding/Decoding 1000+ codec support (H.264, VP9, AAC, etc.) libavformat Container I/O 300+ formats (MP4, MKV, MP3, etc.) libavdevice Device I/O Webcams, capture cards, framebuffer libavfilter Filtering Video/audio effects (blur, crop, mix) libswscale Image Scaling Color conversion, resizing libswresample Audio Processing Resampling, mixing, format conversion libpostproc Postprocessing Legacy video filters (deblocking)

im on Windows with version 6.8.2 Thanks for letting me know! I figured out another work around so for now I should be good!